The invention relates to a bumper component made of fiber-reinforced material for automobiles or the like. Such component is secured to a vehicle chassis and supports or carries the impact absorbing component.
Today, bumper components or support members for bumpers of automobiles are being made more and more of fiber-reinforced material. Fiber-reinforced materials, for example a composite of glass fibers and resin, have a light weight and simultaneously a high mechanical strength or load capacity. Such bumpers replace conventional bumpers made of metal, as described, for instance in German Patent Publication (DE-OS) No. 2,746,235. Bumpers made of metal have a low bending strength and a low flexural stiffness, Besides, they are heavy.
German Patent Publication (DE-OS) No. 2,754,867 may be taken as an example of bumper support members made of fiber-reinforced material. This known bumper has an approximately U-shaped cross-section and is constructed of resin impregnated fiberglass mats with an unoriented glass fiber component and a component of endless or rather, cut and thereby oriented, glass fibers. The production of such bumper support members can be automated, whereby the resin soaked or impregnated fiberglass mats are inserted into a tool, by means of which the fiberglass mats are then placed onto an appropriately shaped mold whereupon they are molded by compression.
According to German Patent Publication (DE-OS) No. 2,650,096 a similarly U-shaped profiled bumper support member made of fiber-reinforced material may be reinforced in the area of the horizontal walls. A securing element, e.g., for a trailer coupling or a towing eye may then be secured in the area of this reinforcement. This type of structure uses the tensile strength of fiber-reinforced materials so that no further securing points, e.g. a trailer coupling or a towing eye or lug must be provided on the frame components of the automobile or the like.
The production of such bumper support members made of U-profiles or sections of fiber-reinforced material, even with considerable automation, is still complicated. Thus, complex tools must be available for cutting the impregnated fiber mats to size and for then inserting the cut shapes into the actual pressing tool. These operations are, however, still often performed by hand.
It is further known from German Patent Publication (DE-OS) No. 2,261,447 to use a winding technique for producing bumpers made of fiber-reinforced material. In this known method pre-stressed glass fibers coated with a hardening synthetic material are wound around a removable box-shaped core, so that the winding portions extending in horizontal planes and in parallel to each other determine the height of the bumper. After the completion of the winding operation, the thus produced wound body is separated into two parts by a cut along its lengthwise axis, so that two bumper support members with respective U-profiles or sections result. Difficulties arise, however, along the lengthwise edges of the cut-open profile, at which the bumpers must be attached to a vehicle chassis. The bumper can fray along these edges and under such conditions additional sheathing must be provided for the attachment or securing.